There are many instances in the communication industry environment where it is desirable to have an alternate communication channel. If this alternate communication channel is to be effectively ued without loss of significant amounts of data, this alternate channel must be maintained in a ON or "hot" standby condition. Thus, the spare communication channel is utilizing or consuming power even though it is not in active service. As will be realized by those skilled in the art, the standby amplifier or standby communication channel exists not only at the transmission end and at the receiving end, but typically at the intermediate relay stations or transceivers between the transmitter and the ultimate end user.
The present invention utilizes a realization that a lower than "normal" or "optimum" bias voltage applied to a given amplifier stage reduces the power consumption with only a minor degradation in quality of linearity of the output signal as compared to the input signal. In other words, the signal is only slightly more distorted at a low bias voltage level, while the power consumption is substantially reduced. If the standby amplifier has one or more output stages with a reduced bias voltage applied during the standby condition, the amplifier can be switched into service in less time than it takes to bring up an amplifier from a "cold" condition. Although the changing from a low bias somewhat distorted signal to a normal bias level is extremely quick and often is less than any switching requirements existent, the amplifier could operate in the somewhat distorted signal condition momentarily and still provide satisfactory service. In any event, power consumption requirements are substantially reduced for the total apparatus, and the amplifier which was previously in active use and has been switched to standby, would typically be changed to the lower bias condition so that it would save on power consumption.
It is thus an object of the present invention to provide improved power consumption efficiencies in standby amplifier circuits.